This invention relates to continuous motion machines for forming openings in can ends and for sealing the openings by applying manually removable lengths of tape across the openings.
A known prior art machine of this type is the Scotch Tab I machine built by Remmele Engineering Company of St. Paul, Minn., the taping means for which is described in U.S. Pat. No. 3,750,511. That machine, like the invention described herein, includes transport means adapted for releasably engaging and moving a plurality of can ends seriatim along a predetermined path, feeding means for feeding can ends to the transport means at a beginning position along the path, opening forming means for forming openings in the can ends moving along the path, taping means mounted along the path for applying lengths of tape across the formed openings, and removing means for removing the completed can ends from the transport means.
In that machine, unlike the present invention, however, the transport means is a chain-like conveyor having can end locating fixtures attached thereto, with each fixture supporting a can end in a horizontal position on upwardly projecting pins. The connections between portions of the conveyor wear, thus causing the conveyor to elongate and the spacing between the can ends to increase so that the accuracy with which the opening forming means and the taping means engage the can ends is affected. Additionally the transport means lacks versatility in that it is difficult to change the locations at which the opening forming means and taping means form the sealed opening in the can end, such as from an edge to a central location. Also it is difficult to apply tape to both sides of the opening in the can end as may be desirable so that the inner tape will separate the contents of a can from the unplated severed edge of the opening and thereby prevent corrosion of that edge.